Research Description

I am interested in the genetic basis of adaptation and speciation, and the evolutionary forces responsible for these processes. Despite more than a century and a half of research, we still understand little about Darwin’s ‘mystery of mysteries’ – the origin of new species. Many basic questions remain: What drives diversification and speciation in natural systems? What is the genetic basis of reproductive incompatibility? How important are adaptive processes in the evolution of reproductive barriers? Do dominant modes of speciation differ among diverse biological systems?

Our approaches to these questions include empirical studies of micro-evolutionary divergence, genetic analyses of trait variation and interspecific sterility, and comparative analyses of macro-evolutionary patterns. Past and current research has included both model and non-model plant groups, and new promising systems are always welcome. Some current research interests include:

Genetics of Reproductive Barriers and Hybrid Sterility:Using QTL (Quantitative Trait Locus) mapping, we have been identifying genomic regions that are responsible for hybrid sterility and other ecologically important trait differences between species. This research primarily focuses on the plant group that includes the domesticated tomato: Solanum Sect. Lycopersicon. Because of its genetic and genomic resources, and its many ecologically diverse wild species, this is a great system to examine ecological and evolutionary questions. One of the goals of this work is to identify and isolate individual genes responsible for adaptation and for hybrid barriers (so-called ‘speciation genes’), and to understand the forces that have shaped the evolution of these genes.

Comparative Genomics of Adaptation and Speciation:Combining data from several QTL mapping studies, we are examining the genetic changes responsible for adaptive and reproductive differences between multiple closely-related species in Solanum. We aim to identify general patterns of adaptation and the evolution of reproductive barriers. Some of our key questions in this research include: What is the connection between genes underlying adaptation and genes causing reproductive barriers between species? Are the same genetic changes, classes of genes, or regions of the genome, repeatedly involved in adaptation and speciation? How does the accumulation of species differences change with increasing evolutionary divergence?